#include<stdio.h>
#include<string.h>
#include<ctype.h>

int main()
{
    char s[21];
    fgets(s, sizeof(s), stdin);
    
    int len = strlen(s);
    if (len >0 && s[len-1] =='\n') s[len - 1]='\0'
    
    for (int i=0; s[i]; i++){
        if (!isalpha(s[i])&& s[i]!=' ')
        printf("Invalid input\n");
        return 0;
        
    }
    
}
char* token = strtok(s,"");
char* last_word = token;
while (token) {
    last_word = token;
    token = strtok(NULL," ");
    
}
if (last_word)
    printf("%d\n", (int)strlen(last_word))
else
    print("0\n");
return 0;